1. Field of the Invention
The present invention relates to an inductor, and specifically to a coil-type inductor.
2. Description of the Related Art
Inductors do not permit high-frequency components to easily pass through and are therefore used in filters and power circuits for noise elimination, smoothing, etc. Inductors are structurally classified into the coil type, laminated type, thin-membrane type, etc., among which, coil-type inductors are frequently used particularly in DC-DC converters and other applications where large current is applied.
Recent years have seen a growing demand for smaller inductors with an increase in the component mounting density of electronic devices. However, a smaller inductor means a reduced volume of the inductor core (core made of magnetic material), which makes the inductor prone to deterioration of DC superimposition characteristics (inductance when a DC current load is applied).
As a result, inductors whose DC superimposition characteristics will not deteriorate even when the inductor size is reduced, are desired.
Patent Literature 1 mentioned below discloses a technology relating to a mold coil whose structure is such that the coil is sealed by magnetic mold resin (resin with magnetic powder dispersed in it) (hereinafter referred to as “prior art”). It is stated that, according to this prior art, excellent DC superimposition characteristics can be obtained (Paragraph [0011] in the literature).